n = input()
p = 0
Ans = []
for i in range(len(n)):
    a = int(n[i])
    if a > 5:
        print("".join(Ans)+"5"*(len(n)-len(Ans)))
        break
    elif a == 5:
        Ans.append("5")
        p = 1
    elif a == 4:
        Ans.append("4")
    else:
        if not p:
            print("5"*(len(n)-1))
            break
        else:
            while Ans[-1] == "4":
                Ans.pop()
            Ans[-1] = "4"
            print("".join(Ans)+"5"*(len(n)-len(Ans)))
        break
else:
    print("".join(Ans))